Wouldn't start (for no apparent reason). Then finally did (for no apparent reason!)

[prayforsurf0]

I take good car of my old girl. She's old and got plenty of miles, but runs beautifully, and I know her purr well and can hear in a second an issues I need to check out or fix. She's my girl and I know her well.

I was stumped this morning when I went to start her and she just turned over with zero sign of starting. Just cranking and cranking. Grabbed some starter fluid right away and sprayed to see if it was a fuel issue. Again, not even a hint at starting. Maybe I didn't get the spray deep enough in the intake ? Sprayed again. Still nothing.

This was making me think it was a spark issue, but I wanted to spray once more, so I did. She cranked for a while (5-10 seconds?) and then finally started up and sounded great. Just like normal. She continues to start up as if the problem never occurred.

Wondering what could have possibly caused such an issue ? Why am I not still struggling to start her after having turned her off ? Seems weird to have a problem that disappears as if it never happened.

Thanks in advance for your insights!

 

[imp]

I take good car of my old girl. She's old and got plenty of miles, but runs beautifully, and I know her purr well and can hear in a second an issues I need to check out or fix. She's my girl and I know her well.

I was stumped this morning when I went to start her and she just turned over with zero sign of starting. Just cranking and cranking. Grabbed some starter fluid right away and sprayed to see if it was a fuel issue. Again, not even a hint at starting. Maybe I didn't get the spray deep enough in the intake ? Sprayed again. Still nothing.

This was making me think it was a spark issue, but I wanted to spray once more, so I did. She cranked for a while (5-10 seconds?) and then finally started up and sounded great. Just like normal. She continues to start up as if the problem never occurred.

Wondering what could have possibly caused such an issue ? Why am I not still struggling to start her after having turned her off ? Seems weird to have a problem that disappears as if it never happened.

Thanks in advance for your insights!

@prayforsurf0

Well, lessee now.....no help at all from starting fluid, rules out lack of fuel, which rules out pretty much fuse, relay, inertial switch, and pump. Ignition: was anything wetted down by water underhood? No.

Check out the primary wiring to the ign. coil. I've seen, though rarely, a frayed wire grounded lightly against something shiny, cranking engine wiggled it, sometimes breaking the ground-out, and got ign. This is fairly unlikely.

Data to PCM: Without crankshaft position data, PCM won't start the engine. Check for looseness of the Crank Position Sensor connector. Look for wiring trouble between there and PCM.

"NO APPARENT REASON" (?) Usually, there isn't one very apparent. That's what makes all this so much fun! imp

 

[Hacra]

Wouldn't PATS issues cause something like this?

 

[J_C]

PATs would rapidly blink the dash light.

I'd check the fuel pressure. You didn't mention your engine but if it's the 4.0L on a '98 it should be around 35PSI. You might have a bad fuel pump, intermittently working.

Next I'd check for spark at the coils.